/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.log4j.chainsaw;

import java.awt.BorderLayout;
import java.text.MessageFormat;
import java.util.Date;
import javax.swing.BorderFactory;
import javax.swing.JEditorPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import org.apache.log4j.Logger;

/**
 * A panel for showing a stack trace.
 * 
 * @author <a href="mailto:oliver@puppycrawl.com">Oliver Burn</a>
 */
class DetailPanel extends JPanel implements ListSelectionListener {
	/** used to log events **/
	private static final Logger LOG = Logger.getLogger(DetailPanel.class);

	/** used to format the logging event **/
	private static final MessageFormat FORMATTER = new MessageFormat(
			"<b>Time:</b> <code>{0,time,medium}</code>"
					+ "&nbsp;&nbsp;<b>Priority:</b> <code>{1}</code>"
					+ "&nbsp;&nbsp;<b>Thread:</b> <code>{2}</code>"
					+ "&nbsp;&nbsp;<b>NDC:</b> <code>{3}</code>"
					+ "<br><b>Logger:</b> <code>{4}</code>"
					+ "<br><b>Location:</b> <code>{5}</code>"
					+ "<br><b>Message:</b>" + "<pre>{6}</pre>"
					+ "<b>Throwable:</b>" + "<pre>{7}</pre>");

	/** the model for the data to render **/
	private final MyTableModel mModel;
	/** pane for rendering detail **/
	private final JEditorPane mDetails;

	/**
	 * Creates a new <code>DetailPanel</code> instance.
	 * 
	 * @param aTable
	 *            the table to listen for selections on
	 * @param aModel
	 *            the model backing the table
	 */
	DetailPanel(JTable aTable, final MyTableModel aModel) {
		mModel = aModel;
		setLayout(new BorderLayout());
		setBorder(BorderFactory.createTitledBorder("Details: "));

		mDetails = new JEditorPane();
		mDetails.setEditable(false);
		mDetails.setContentType("text/html");
		add(new JScrollPane(mDetails), BorderLayout.CENTER);

		final ListSelectionModel rowSM = aTable.getSelectionModel();
		rowSM.addListSelectionListener(this);
	}

	/** @see ListSelectionListener **/
	public void valueChanged(ListSelectionEvent aEvent) {
		// Ignore extra messages.
		if (aEvent.getValueIsAdjusting()) {
			return;
		}

		final ListSelectionModel lsm = (ListSelectionModel) aEvent.getSource();
		if (lsm.isSelectionEmpty()) {
			mDetails.setText("Nothing selected");
		} else {
			final int selectedRow = lsm.getMinSelectionIndex();
			final EventDetails e = mModel.getEventDetails(selectedRow);
			final Object[] args = {new Date(e.getTimeStamp()), e.getPriority(),
					escape(e.getThreadName()), escape(e.getNDC()),
					escape(e.getCategoryName()),
					escape(e.getLocationDetails()), escape(e.getMessage()),
					escape(getThrowableStrRep(e))};
			mDetails.setText(FORMATTER.format(args));
			mDetails.setCaretPosition(0);
		}
	}

	////////////////////////////////////////////////////////////////////////////
	// Private methods
	////////////////////////////////////////////////////////////////////////////

	/**
	 * Returns a string representation of a throwable.
	 * 
	 * @param aEvent
	 *            contains the throwable information
	 * @return a <code>String</code> value
	 */
	private static String getThrowableStrRep(EventDetails aEvent) {
		final String[] strs = aEvent.getThrowableStrRep();
		if (strs == null) {
			return null;
		}

		final StringBuffer sb = new StringBuffer();
		for (int i = 0; i < strs.length; i++) {
			sb.append(strs[i]).append("\n");
		}

		return sb.toString();
	}

	/**
	 * Escape &lt;, &gt; &amp; and &quot; as their entities. It is very dumb
	 * about &amp; handling.
	 * 
	 * @param aStr
	 *            the String to escape.
	 * @return the escaped String
	 */
	private String escape(String aStr) {
		if (aStr == null) {
			return null;
		}

		final StringBuffer buf = new StringBuffer();
		for (int i = 0; i < aStr.length(); i++) {
			char c = aStr.charAt(i);
			switch (c) {
				case '<' :
					buf.append("&lt;");
					break;
				case '>' :
					buf.append("&gt;");
					break;
				case '\"' :
					buf.append("&quot;");
					break;
				case '&' :
					buf.append("&amp;");
					break;
				default :
					buf.append(c);
					break;
			}
		}
		return buf.toString();
	}
}
